230 research outputs found

    Development of a new method to estimate the incident solar flux on central receivers from deteriorated heliostats

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    This work proposes a new empirical direct methodology to estimate both the solar flux distribution and intensity on the surface of central receivers. In solar power tower plants with deteriorated heliostats, the numerical simulations to estimate the incident solar flux are not precise. Hence the thermal behaviour of the receivers cannot be determined. In those cases, direct measurement or semi-empirical methodologies are required to characterize the radiant power on the receiver. The new methodology proposed, named "Superposition method", consists in the hourly characterization of the reflected solar beam of each individual heliostat by means of a pyrheliometer, a passive screen, a flux sensor, a camera and digital image analysis. According to the aiming strategy used during receiver operation, each individual solar flux distribution and intensity can be gathered to obtain the total incident radiant power on the solar receiver. This non-real-time method has the advantage of reproducing any solar flux distribution on the receiver at present and past time

    Evidence for weak electronic correlations in Fe-pnictides

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    Using x-ray absorption and resonant inelastic x-ray scattering, charge dynamics at and near the Fe LL edges is investigated in Fe pnictide materials, and contrasted to that measured in other Fe compounds. It is shown that the XAS and RIXS spectra for 122 and 1111 Fe pnictides are each qualitatively similar to Fe metal. Cluster diagonalization, multiplet, and density-functional calculations show that Coulomb correlations are much smaller than in the cuprates, highlighting the role of Fe metallicity and strong covalency in these materials. Best agreement with experiment is obtained using Hubbard parameters U≲2U\lesssim 2eV and J≈0.8J\approx 0.8eV.Comment: 11 pages, 12 figure

    Nivel de proteína C reactiva en pacientes con obesidad mórbida antes y después de cirugía bariátrica

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    ResumenAntecedentesLa obesidad humana se asocia a un estado proinflamatorio reflejado en elevación de marcadores como la proteína C reactiva (PCR).ObjetivosEstablecer los valores de PCR basales y a 6 meses de la cirugía bariátrica, así como los cambios en peso, índice de masa corporal (IMC), leucocitos y glucemia.Materiales y métodosSe realizó un estudio observacional, analítico, retrospectivo, longitudinal y abierto. Se midieron los valores de PCR sérica y su relación con el peso, IMC, leucocitos y glucemia de manera basal y 6 meses posteriores a cirugía bariátrica en 36 adultos con obesidad mórbida.ResultadosLa media ± desviación estándar de la PCR pre y posoperatorio (mg/l) fue 1.15±0.86 y 0.34±0.28, respectivamente, con p<0.0001; peso (kg) 112.10±22.91 y 84.82±17.11, p=0,0443; IMC (kg/m2) 42.48±5.97 y 32.2±4.79, p=0.0988; glucosa (mg/dl) 100.58±17.82 y 87.11±8.49, p<0.0001, y leucocitos (× 103/mm3) 8.62±1.69 y 6.99±1.56, p=0.3192.La PCR basal solo correlacionó con el peso e IMC (p=0.047 y p=0.027, respectivamente) y no hubo correlación entre la PCR posoperatoria y ninguno de los parámetros evaluados.ConclusionesLa PCR tiene una relación lineal significativa en el preoperatorio con el peso y el IMC. Los pacientes sometidos a cirugía bariátrica presentaron disminución significativa en la PCR, el peso y la glucemia en ayuno a los 6 meses posterior a la cirugía.AbstractBackgroundHuman obesity is associated with a proinflammatory state and an elevated level of mediators, such as C-reactive protein (CRP).ObjectivesTo establish CRP levels as baseline preoperative values and then at 6 months after bariatric surgery, as well as to determine the changes in weight, body mass index (BMI), leukocytes, and glycemia.Materials and methodsAn observational, analytical, retrospective, longitudinal, and open study was conducted. Serum CRP values were measured in 36 adults presenting with morbid obesity, and their baseline relation to weight, BMI, leukocytes, and glycemia was determined; the relation to the same parameters was established again, 6 months after bariatric surgery.ResultsThe mean and standard deviation of preoperative and postoperative CRP (mg/L) was 1.15±0.86 and 0.34±0.28, respectively with p<0.0001; weight (kg) 112.10±22.91 and 84.82±17.11, p=0.0443; BMI (kg/m2) 42.48±5.97 and 32.2±4.79, p=0.0988; glucose (mg/dL) 100.58±17.82 and 87.11±8.49, p<0.0001, and leukocytes (× 103/mm3) 8.62±1.69 and 6.99±1.56, p=0.3192.Baseline CRP only correlated with weight and BMI (p=0.047 and p=0.027 respectively) and there was no correlation between postoperative CRP and the evaluated parameters.ConclusionsPreoperative CRP had a significant lineal relation to weight and body mass index. Patients who underwent bariatric surgery had a significant decrease in CRP, weight, and fasting glucose at 6 months after surgery

    Spin-Orbit-Induced Orbital Excitations in Sr2RuO4 and Ca2RuO4: A Resonant Inelastic X-ray Scattering Study

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    High-resolution resonant inelastic X-ray scattering (RIXS) at the oxygen K-edge has been used to study the orbital excitations of Ca2RuO4 and Sr2RuO4. In combination with linear dichroism X-ray absorption spectroscopy, the ruthenium 4d-orbital occupation and excitations were probed through their hybridization with the oxygen p-orbitals. These results are described within a minimal model, taking into account crystal field splitting and a spin-orbit coupling \lambda_{so}=200~meV. The effects of spin-orbit interaction on the electronic structure and implications for the Mott and superconducting ground states of (Ca,Sr)2RuO4 are discussed.Comment: accepted in PRB 201

    A Common Genetic Origin for Early Farmers from Mediterranean Cardial and Central European LBK Cultures

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    The spread of farming out of the Balkans and into the rest of Europe followed two distinct routes: An initial expansión represented by the Impressa and Cardial traditions, which followed the Northern Mediterranean coastline; and another expansion represented by the LBK (Linearbandkeramik) tradition, which followed the Danube River into Central Europe. Although genomic data now exist from samples representing the second migration, such data have yet to be successfully generated from the initial Mediterranean migration. To address this, we generated the complete genome of a 7,400-yearold Cardial individual (CB13) from Cova Bonica in Vallirana (Barcelona), as well as partial nuclear data from five others excavated from different sites in Spain and Portugal. CB13 clusters with all previously sequenced early European farmers and modern-day Sardinians. Furthermore, our analyses suggest that both Cardial and LBK peoples derived from a common ancient population located in or around the Balkan Peninsula. The Iberian Cardial genome also carries a discernible huntergatherer genetic signature that likely was not acquired by admixture with local Iberian foragers. Our results indicate that retrieving ancient genomes from similarly warm Mediterranean environments such as the Near East is technically feasible

    'Ava’: a Beaker-associated woman from a cist at Achavanich, Highland, and the story of her (re-) discovery and subsequent study

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    This contribution describes the discovery and subsequent investigation of a cist in a rock-cut pit at Achavanich, Highland. Discovered and excavated in 1987, the cist was found to contain the tightly contracted skeletal remains of a young woman, accompanied by a Beaker, three flint artefacts and a cattle scapula. Initial post excavation work established a date for the skeleton together with details of her age and sex, and preliminary pollen analysis of sediments attaching to the Beaker was undertaken. The findings were never fully published and, upon the death of the excavator, Robert Gourlay, the documentary archive was left in the Highland Council Archaeology Unit. Fresh research in 2014–17, initiated and co-ordinated by the first-named author and funded by the Society of Antiquaries of Scotland with assistance from National Museums Scotland, the Natural History Museum and Harvard Medical School, has produced a significant amount of new information on the individual and on some of the items with which she was buried. This new information includes two further radiocarbon dates, a more detailed osteological report, isotopic information pertaining to the place where she had been raised and to her diet, histological information on the decomposition of her body, and genetic information that sheds light on her ancestry, her hair, eye and skin colour and her intolerance of lactose. (This is the first time that an ancient DNA report has been published in the Proceedings.) Moreover, a facial reconstruction adds virtual flesh to her bones. The significance of this discovery within the Chalcolithic to Early Bronze Age of this part of Scotland is discussed, along with the many and innovative ways in which information on this individual, dubbed ‘Ava’, has been disseminated around the world.Copyright © 2018 rests with the Society and the individual authors. Except where otherwise noted, this work is licensed under CreativeCommons Attribution-NonCommercial-No Derivatives licence.https://creativecommons.org/licenses/by-nc-nd/4.0/ The permission to reproduce the Society's copyright-protected ma-terial does not extend to any material which is identified as being the copyright of a third party. Authorisation to reproduce such material must be obtained from the copyright holders concerned. The attached file is the published pdf

    Genomic analysis of 18th-century kazakh individuals and their oral microbiome

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    The Asian Central Steppe, consisting of current-day Kazakhstan and Russia, has acted as a highway for major migrations throughout history. Therefore, describing the genetic composition of past populations in Central Asia holds value to understanding human mobility in this pivotal region. In this study, we analyse paleogenomic data generated from five humans from Kuygenzhar, Kazakhstan. These individuals date to the early to mid-18th century, shortly after the Kazakh Khanate was founded, a union of nomadic tribes of Mongol Golden Horde and Turkic origins. Genomic analysis identifies that these individuals are admixed with varying proportions of East Asian ancestry, indicating a recent admixture event from East Asia. The high amounts of DNA from the anaerobic Gram-negative bacteria Tannerella forsythia, a periodontal pathogen, recovered from their teeth suggest they may have suffered from periodontitis disease. Genomic analysis of this bacterium identified recently evolved virulence and glycosylation genes including the presence of antibiotic resistance genes predating the antibiotic era. This study provides an integrated analysis of individuals with a diet mostly based on meat (mainly horse and lamb), milk, and dairy products and their oral microbiome

    Massive migration from the steppe is a source for Indo-European languages in Europe

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    We generated genome-wide data from 69 Europeans who lived between 8,000-3,000 years ago by enriching ancient DNA libraries for a target set of almost four hundred thousand polymorphisms. Enrichment of these positions decreases the sequencing required for genome-wide ancient DNA analysis by a median of around 250-fold, allowing us to study an order of magnitude more individuals than previous studies and to obtain new insights about the past. We show that the populations of western and far eastern Europe followed opposite trajectories between 8,000-5,000 years ago. At the beginning of the Neolithic period in Europe, ~8,000-7,000 years ago, closely related groups of early farmers appeared in Germany, Hungary, and Spain, different from indigenous hunter-gatherers, whereas Russia was inhabited by a distinctive population of hunter-gatherers with high affinity to a ~24,000 year old Siberian6 . By ~6,000-5,000 years ago, a resurgence of hunter-gatherer ancestry had occurred throughout much of Europe, but in Russia, the Yamnaya steppe herders of this time were descended not only from the preceding eastern European hunter-gatherers, but from a population of Near Eastern ancestry. Western and Eastern Europe came into contact ~4,500 years ago, as the Late Neolithic Corded Ware people from Germany traced ~3/4 of their ancestry to the Yamnaya, documenting a massive migration into the heartland of Europe from its eastern periphery. This steppe ancestry persisted in all sampled central Europeans until at least ~3,000 years ago, and is ubiquitous in present-day Europeans. These results provide support for the theory of a steppe origin of at least some of the Indo-European languages of Europe

    Look-alike humans identified by facial recognition algorithms show genetic similarities

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    We thank François Brunelle for providing the look-alike images. We thank CERCA Programme/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. This work was funded by the governments of Catalonia (2017SGR1080) and Spain (RTI2018-094049-B-I00, SAF2014-55000, and TIN2017-90124-P) and the Cellex Foundation. M.E. conceived and designed the study; R.S.J. M.R. C.A.G.-P. M.C.d.M. D.P. S.M. V.D. P.C. M.F.-B. I.O. C.L.-F. A.N. C.F.-T. D.A. F.M.S. X.B. A.V. and M.E. analyzed multiomics and questionnaire data; R.J. and M.E. wrote the manuscript with contributions and approval from all authors. M.E. is a consultant of Ferrer International and Quimatryx. S.M. is an employee of Ferrer International. C.F.-T. is chief technical officer of Herta Security.We thank François Brunelle for providing the look-alike images. We thank CERCA Programme/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. This work was funded by the governments of Catalonia (2017SGR1080) and Spain (RTI2018-094049-B-I00, SAF2014-55000, and TIN2017-90124-P) and the Cellex Foundation.The human face is one of the most visible features of our unique identity as individuals. Interestingly, monozygotic twins share almost identical facial traits and the same DNA sequence but could exhibit differences in other biometrical parameters. The expansion of the world wide web and the possibility to exchange pictures of humans across the planet has increased the number of people identified online as virtual twins or doubles that are not family related. Herein, we have characterized in detail a set of "look-alike" humans, defined by facial recognition algorithms, for their multiomics landscape. We report that these individuals share similar genotypes and differ in their DNA methylation and microbiome landscape. These results not only provide insights about the genetics that determine our face but also might have implications for the establishment of other human anthropometric properties and even personality characteristics
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